A. Whether Article 536 of the Civil Act concerning simultaneous performance applies mutatis mutandis where each party has to return a bilateral contract invalidated and each party has to acquire it (affirmative)

B. In a case where a bilateral contract is cancelled, whether a bona fide seller needs to return the sales profit of the purchase price or legal interest (negative)

A. Article 536 of the Civil Code, which provides a right to defense of simultaneous performance, applies mutatis mutandis to the duty to restore each party in case of rescission of a contract pursuant to Article 549 of the Civil Code, even if a bilateral contract becomes null and void and each party shall return each other's acquisition of bilateral contract, deeming that there is a simultaneous performance relationship and applying Article 536 of the Civil Code mutatis mutandis. This is because, in light of the concept of fairness, there is no reason to distinguish between the duty to reinstate when a contract becomes null and void and that at the time of cancellation of a contract, if the duty to return is enforced first only to either party, it is contrary to the principle of fairness

B. In the event that a bilateral contract is cancelled, as long as Article 201 of the Civil Act applies to a bona fide buyer and the right to acquire negligence is recognized, the bona fide seller shall also be held in accordance with the principle of equity to deny the return of operating profit or statutory interest by analogy of Article 587 of the Civil Act

A. Articles 536 and 549 of the Civil Act; Articles 587 and 748 of the Civil Act

A. Supreme Court Decision 75Da1241 delivered on April 27, 1976 (Gong1976, 9130)

[Defendant-Appellee] Plaintiff 1 et al.

Changwon-si, Attorney Kim Young-han, Counsel for the defendant-appellant

Changwon District Court Decision 92Na1265 delivered on September 4, 1992

The appeal is dismissed.

The costs of appeal are assessed against the defendant.

Defendant 1’s ground of appeal

1. The court below, based on adopted evidence, recognized that the whole land of this case, including the remaining land of this case, was incorporated into the defendant's land subject to business, and that the plaintiff would be forced to accept the defendant's request for consultation even if it is not transferred at will to the defendant's business. Such fact-finding is acceptable, and there is no error in the rules of evidence against the rules of evidence in the process. Meanwhile, the court below rejected the plaintiff's assertion that there was no error in the misapprehension of the legal principles as to the remaining part of the consultation on expropriation of this case from the defendant's name and there was no error in the misapprehension of the rules of evidence against the plaintiff's declaration of intention of cancellation. The plaintiff's right to cancel the registration of transfer of ownership in this case was exceeded 3 years after the date of the above registration was completed (3.15 of the court below's decision) and there was no error in the misapprehension of the legal principles as to the plaintiff's expression of intent or the right of defense as to this case's land in this case's name.

There is no reason to discuss this issue.

2. The purpose of Article 536 of the Civil Act, which provides for the right to defense of simultaneous performance, is due to the merger between the concept of fairness and the principle of good faith, and Article 536 of the Civil Act applies mutatis mutandis to the duty to restore each party in the case of rescission of a contract pursuant to Article 549 of the Civil Act, it is interpreted that the simultaneous performance relationship exists even in the case where each party has to return a bilateral contract which becomes null and void and thus each party has to acquire, and that Article 536 of the Civil Act shall apply mutatis mutandis to the case where each party has to return a bilateral contract. In light of the concept of fairness, there is no reason to distinguish between the duty to reinstate when the contract becomes null and void and the duty to cancel the contract from the case where the contract is void, and if the return obligation is enforced first to either party, it is in violation of the principle of fairness and good faith (see

Therefore, the lower court’s judgment that the Plaintiff’s obligation to return the purchase price and the Defendant’s obligation to cancel the ownership transfer registration to be borne by the cancellation of the instant sales contract is justifiable.

In addition, the lower court made a decision to the effect that the Plaintiff is a bona fide beneficiary, and thus, it does not need to return the interest added thereto. This is also justifiable in that, inasmuch as Article 201 of the Civil Act applies to a bona fide buyer when a bilateral contract is revoked, so long as the right to acquire negligence is recognized, the bona fide seller would also deny the return of operating profit or statutory interest by analogical application of Article 587 of the

Therefore, the appeal is dismissed and all costs of appeal are assessed against the losing party. It is so decided as per Disposition by the assent of all participating Justices on the bench.

Justices Yoon Young-young (Presiding Justice)